Archive an app

It could be nice if we could archive an app and having possibility to reactivate it if we want. And it could be interesting to have a stop button to stop an app (we can do it with the CLI) when the load average is to high for example.

We used to have that button in the UI but we do not have an explicit "stopped by user" state, the platform would attempt to start all apps on reboot or such, in case an app was down for some reason. Maybe we should be adding a new explicit state for this archive feature? Generally we try to avoid cluttering the UI with such advanced features, but I think it makes sense for self-servicing the Cloudron better.